Cancer is prevalent: Among United States citizens that live to be 70 years older and older, the probability of developing invasive cancer is 38% for females and 46% for males. According to the American Cancer Society, there will be about 1.4 million new cases of cancer in the United States alone in 2006. Although the five year survival rate for all cancers is now 65%, up from about 50% in the mid-nineteen seventies, cancer remains a leading killer today. Indeed, it is estimated that 565,000 people in the United States will die from cancer in 2006. (American Cancer Society, Surveillance Research, 2006). Although numerous treatments are available for various cancers, the fact remains that many cancers remain incurable, untreatable, and/or become resistant to standard therapeutic regimens. Thus, there is a clear need for new cancer treatments employing novel chemotherapeutic compounds.
Inhibitors of the molecular chaperone protein Hsp90 are being developed as one class of pharmacological weaponry in the anticancer chemotherapeutic arsenal. Consequently, there is a clear need for additional, novel, Hsp90 inhibitors for the treatment of diseases and disorders, such as cancer, that respond favorably to the inhibition of Hsp90.